[gooserock]

The idea that building high-income housing makes rents rise is pretty obviously bunk, but the idea that building high-income housing "helps affordability" is not as clear cut. Is it good to increase supply? Yes, of course. But on the other hand, this article fails to mention three phenomena plaguing cities like London, San Francisco, and Vancouver:

1. Speculators. There's been a huge uptick in people from other locales - even internationally - buying or building housing units as investments and literally leaving them empty, expecting them to appreciate in value. These units are effectively not part of the housing stock and don't help with the supply problem.

2. Vacation Homes. As wealth inequality has become more dramatic, the wealthy have more income to spend on vacation homes. In cities like Portland, Maine, Manhattan and San Francisco, many high-end condo buyers are buying these units as vacation destinations that they'll only occupy for a tiny part of the year. These too are not being truly added to the housing supply.

3. Airbnb/Short Term Rentals. I don't want to single out Airbnb here, but it's known to real estate agents and investors that you can make way more money with an Airbnb rental than a long-term rental. (Where I live it's about 5x difference in annual income.) Many new housing units are being eaten by people who use them to operate short-term rentals, which they have an enormous economic incentive to do. These units too are not being added to the long-term housing supply.

[mafribe]

   Where I live it's about 5x difference 
   in annual income.

Is that 5x in total income over the year, or 5x in rent charged? Shorterm rentals have various costs that long-term renting doesn't have, like cleaning, higher repair costs, lack of occupation during off-peak season etc.

[wtvanhest]

Increasing the number of units does not increase demand for speculators, vacation homes or airbnb. Those should be addressed, but in a totally seperate conversation from whether to build more units or not.